Vehicle lateral control system having lane model with modulation weighting and control method thereof

• US 10,633,024 B2
• Filed: 12/27/2017
• Issued: 04/28/2020
• Est. Priority Date: 12/27/2017
• Status: Active Grant

• Current Assignee: Automotive Research & Testing Center
• Original Assignee: Automotive Research & Testing Center
• Inventors: Ku, Kun-Lung, Hsu, Jin-Yan, Lin, Hung-Pang, Jhang, Tong-Kai
• Primary Examiner(s): Cheung, Calvin
• Application Number:
  US15/856,035
• Publication Number:
  US 20190193785A1
• Time in Patent Office: 853 Days
• CPC Class Codes: B60R 16/0231 Circuits relating to the driving or the functioning of the vehicle monitoring tyres B60C23/00; indicating overspeed B60K31/00; for dash boards B60K37/00, B60Q3/10; for indicating emergencies B60Q1/52; brake control systems B60T; registering or indicating the working of vehicles G07C5/00; measuring distance G01C, e.g. combinations of speed and distance G01C23/00; engine indicators G01L; measuring speed or acceleration G01P
• CPC Class Codes: B60W 30/12 Lane keeping
• CPC Class Codes: B62D 15/025 Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation B62D1/28 takes precedence
• CPC Class Codes: G06V 20/588 Recognition of the road, e.g. of lane markings; Recognition of the vehicle driving pattern in relation to the road
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

Abstract

A vehicle lateral control system having a lane model with modulation weighting for controlling a vehicle includes a camera, an image processing device, a controller and a steering device. The camera is configured to capture a front image of the vehicle to generate a front image dataset. The front image dataset is analyzed by the image processing device to obtain a plurality of lane markers, and the image processing device establishes a lane fitting curve according to the lane markers and a target weighting. The controller has a plurality of vehicle dynamic parameters and a target distance. The target weighting is changeable according to the target distance. The controller generates a steering control weighting according to the lane fitting curve and the vehicle dynamic parameters. The steering device is configured to control a turning direction of the vehicle according to the steering control weighting.

Claims

1. A vehicle lateral control system having a lane model with modulation weighting for controlling a vehicle, the vehicle lateral control system comprising:

a camera disposed on the vehicle and faced toward a front of the vehicle, wherein the camera is configured to capture a front image of the vehicle to generate a front image dataset;

an image processing device signally connected to the camera and receives the front image dataset, wherein the front image dataset is analyzed by the image processing device to obtain a plurality of lane markers, and the image processing device establishes a lane fitting curve according to the lane markers and a target weighting;

a controller signally connected to the image processing device and having a plurality of vehicle dynamic parameters and a target distance, wherein the target weighting is changeable according to the target distance, and the controller generates a steering control weighting according to the lane fitting curve and the vehicle dynamic parameters; and

a steering device signally connected to the controller and disposed on the vehicle, wherein the steering device is configured to control a turning direction of the vehicle according to the steering control weighting;

wherein the target weighting within the target distance is greater than the target weighting beyond the target distance.

2. The vehicle lateral control system of claim 1, wherein the steering control weighting of the controller is equal to a lateral offset weighting value, the vehicle is spaced from the lane fitting curve by a lateral offset distance, and the lateral offset weighting value is increased according to an increase of the lateral offset distance.

3. The vehicle lateral control system of claim 1, wherein the steering control weighting of the controller is equal to an estimated lane crossing weighting value, and the controller generates an estimated lane crossing time according to a vehicle speed, an acceleration and a yaw rate of the vehicle;

wherein when the estimated lane crossing time is equal to or smaller than a predetermined time, the estimated lane crossing weighting value is equal to 1;

wherein when the estimated lane crossing time is greater than the predetermined time, the estimated lane crossing weighting value is decreased according to an increase of the estimated lane crossing time.

4. The vehicle lateral control system of claim 1, wherein the steering control weighting of the controller is determined by a maximum value of a lateral offset weighting value and an estimated lane crossing weighting value.

5. The vehicle lateral control system of claim 1, wherein the steering control weighting of the controller comprises a lateral offset weighting value, a first percentage value, an estimated lane crossing weighting value and a second percentage value, the steering control weighting is equal to the lateral offset weighting value multiplied by the first percentage value minus the estimated lane crossing weighting value multiplied by the second percentage value, and the first percentage value plus the second percentage value is equal to 100%.

6. The vehicle lateral control system of claim 1, wherein the steering device comprises:

a current control mechanism configured to apply a driving current, wherein the driving current is adjusted by the current control mechanism according to the steering control weighting;

a driving mechanism electrically connected to the current control mechanism and controlled by the driving current; and

a steering mechanism driven by the driving mechanism, wherein the steering mechanism is configured to control the turning direction of the vehicle according to the driving current.

7. The vehicle lateral control system of claim 6, wherein the driving current is increased according to an increase of the steering control weighting, and the driving current is decreased according to a decrease of the steering control weighting.

8. The vehicle lateral control system of claim 1, wherein the vehicle dynamic parameters comprise a vehicle speed, an acceleration, a yaw rate, a present steering angle and a driving torque.

9. A vehicle lateral control method having a lane model with modulation weighting for controlling a vehicle, the vehicle lateral control method comprising:

providing an image capturing step, wherein the image capturing step is for capturing a front image of the vehicle to generate a front image dataset by a camera;

providing an image processing step, wherein the image processing step is for receiving the front image dataset and analyzing the front image dataset by the image processing device to obtain a plurality of lane markers, and the image processing device establishes a lane fitting curve according to the lane markers and a target weighting;

providing a control weighting generating step, wherein the control weighting generating step is for generating a steering control weighting according to the lane fitting curve and a plurality of vehicle dynamic parameters by a controller, the controller has the vehicle dynamic parameters and a target distance, and the target weighting is changeable according to the target distance; and

providing a steering control step, wherein the steering control step is for controlling a turning direction of the vehicle according to the steering control weighting by a steering device;

wherein in the control weighting generating step, the target weighting within the target distance is greater than the target weighting beyond the target distance.

10. The vehicle lateral control method of claim 9, wherein,

in the control weighting generating step, the steering control weighting of the controller is equal to a lateral offset weighting value, the vehicle is spaced from the lane fitting curve by a lateral offset distance, and the lateral offset weighting value is increased according to an increase of the lateral offset distance.

11. The vehicle lateral control method of claim 9, wherein,

in the control weighting generating step, the steering control weighting of the controller is equal to an estimated lane crossing weighting value, and the controller generates an estimated lane crossing time according to a vehicle speed, an acceleration and a yaw rate of the vehicle;

wherein when the estimated lane crossing time is equal to or smaller than a predetermined time, the estimated lane crossing weighting value is equal to 1;

wherein when the estimated lane crossing time is greater than the predetermined time, the estimated lane crossing weighting value is decreased according to an increase of the estimated lane crossing time.

12. The vehicle lateral control method of claim 9, wherein,

in the control weighting generating step, the steering control weighting of the controller is determined by a maximum value of a lateral offset weighting value and an estimated lane crossing weighting value.

13. The vehicle lateral control method of claim 9, wherein,

in the control weighting generating step, the steering control weighting of the controller comprises a lateral offset weighting value, a first percentage value, an estimated lane crossing weighting value and a second percentage value, the steering control weighting is equal to the lateral offset weighting value multiplied by the first percentage value minus the estimated lane crossing weighting value multiplied by the second percentage value, and the first percentage value plus the second percentage value is equal to 100%.

14. The vehicle lateral control method of claim 9, wherein the steering control step comprises:

providing a current controlling sub-step, wherein the current controlling sub-step is for adjusting a driving current by a current control mechanism according to the steering control weighting;

providing a driving sub-step, wherein the driving sub-step is for controlling a driving mechanism by the driving current; and

providing a steering sub-step, wherein the steering sub-step is for driving a steering mechanism by the driving mechanism, and the steering mechanism is configured to control the turning direction of the vehicle according to the driving current.

15. The vehicle lateral control method of claim 14, wherein,

in the steering control step, the driving current is increased according to an increase of the steering control weighting, and the driving current is decreased according to a decrease of the steering control weighting.